1. Field of Invention
This invention relates generally to poultry processing and, more particularly, to harvesting usable parts of a poultry vascular system from the viscera.
2. Background Art
Various usable parts of the vascular system are harvested from the viscera of a poultry carcass. Particularly the heart and the liver are harvested from the viscera pack or more specifically what is generally referred to as the giblet package. The giblet package comprises the gizzard, liver, lungs, heart, intestines and vent. The natural structure of the package comprises two different kind of connections between the organs contained in the viscera. There are functional connections comprising the esophagus to the pre-stomach, the pre-stomach to the gizzard, and the gizzard to the duodenum. The are also major membrane or fleece connections between the liver and gizzard, between the package and crop, and between the heart and liver. In the past, the separation of the usable parts such as the liver and heart from the package was performed by a manual operation. For example, an operator would sever the connection between the liver or gizzard and further remove the intestines and other unusable parts such as the lungs. However, the manual operation was manually intensive, inconsistent in quality and not cost effective. It became evident that a mechanical process was needed for harvesting the usable parts of the viscera.
Various mechanical methods have been developed to isolate the liver and heart for separation by capturing certain portions of the package and utilizing the natural and membrane connections to isolate and position other portions of the package such as for example the portion containing the liver and heart. For example, previous methods have been utilized, which include the steps of mechanically stretching the viscera connected to the liver to pull the gall bladder away from the liver and mechanically cutting between the liver and the gall bladder to separate the liver from the viscera and the gall bladder. Previous methods have also included the steps of mechanically stretching the connecting structure connecting the liver to the heart to pull the heart away from the liver and mechanically cutting the connecting structure between the liver and the heart to separate the liver from the heart. Some of these types of methods include conveying poultry along a prescribed conveying path with the viscera still attached to the poultry carcass while pulling the viscera away from the liver to stretch the viscera and pull the gall bladder away from the liver; and finally separating the liver from the viscera by cutting the stretched connecting structure between the liver and the gall bladder.
This type of apparatus can be designed for use with an overhead conveyor used to transport poultry through the eviscerating section of the poultry plant with the carcass head hanging downward. A locating conveyor moving synchronously with the overhead conveyor has been utilized, where a liver positioning guide is utilized for pulling the viscera away from the liver so that the connecting structure between the gall bladder and the liver is stretched to pull the gall bladder away from the liver for separation. A heart positioning guide can be utilized, which engages the connection between the heart and the liver to selectively position the heart. A heart cutoff mechanism can be utilized to cut the heart from the liver, and a liver cutoff mechanism to cut between the liver and the gall bladder to separate the liver from the rest of the viscera. However, a system of this nature provides a poor yield, and often damages the livers.
Various methods and apparatus have been utilized to separate and isolate the usable parts including roller devices and guide devices to stretch and extend the functional and membrane connections for isolating and separating the usable parts. However, previous methods and apparatus have resulted in a poor yield and inconsistent quality. Further many systems require excessive maintenance and include expensive specially designed parts and mechanisms. A better system is needed considering the market demand for livers has steadily increased. In the past the amount of labor required was directly related to the ability to produce a quality product for customers. The fully automatic liver harvester systems that have been utilized do not address this issue and do not produce a consistent yield, and the maintenance and upkeep for the equipment can be very intensive.
By developing a simple system that consistently produces a higher yield percentage of the total available livers, a manufacture can decrease their cost and labor associated with the fully automatic system and standardize the liver harvesting system to consistently produce a higher quality product. Therefore, the problems of significant damage to the livers, use excessive amounts of water, and specialized parts and added labor, can be resolved.